Trinity, California Air Quality
Trinity County, California (CA)
↑ Worseningover 10 years
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days). Air quality in this area has been declining over the past decade.
Air Quality Day Breakdown
Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).
Year-by-Year Data
| Year | Median AQI | 90th Pct | Max AQI | Good Days | Moderate | Unhealthy+ | Pollutant |
|---|---|---|---|---|---|---|---|
| 2023 | 31 | 65 | 174 | 209 | 93 | 9 | PM2.5 |
| 2022 | 34 | 72 | 342 | 227 | 111 | 15 | PM2.5 |
| 2021 | 38 | 168 | 1217 | 201 | 81 | 46 | PM2.5 |
| 2020 | 36 | 81 | 211 | 215 | 100 | 28 | PM2.5 |
| 2019 | 23 | 56 | 113 | 225 | 42 | 2 | PM2.5 |
| 2018 | 54 | 82 | 209 | 117 | 155 | 19 | PM2.5 |
| 2017 | 57 | 91 | 844 | 76 | 116 | 11 | PM2.5 |
| 2016 | 51 | 73 | 97 | 83 | 84 | 0 | PM2.5 |
| 2015 | 12 | 29 | 56 | 67 | 1 | 0 | PM2.5 |
| 2014 | 12 | 44 | 90 | 102 | 10 | 0 | PM2.5 |
What This Means for Trinity County Residents
Trinity, California has received an Air Quality Grade of C (51/100) based on a decade of EPA monitoring data. The current median AQI of 31 falls in the "Good" range.
Concerning trends show air quality has been declining, with the median AQI rising by 19 points over the monitoring period. This could be driven by increased development, wildfire smoke, or industrial activity.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 20 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.